Benzethonium　chloride　(BZC)　is　an　antibacterial　compound　with　extensive　applications　in　various　anti-infective　products.　However,　the　feasibility　of　attaining　partial　nitrification　of　municipal　wastewater　using　BZC　has　not　been　reported.　In　this　work,　BZC　was　used　for　the　first　time　to　attain　partial　nitrification.　Batch　experiments　indicated　nitrite　oxidizing　bacteria　(NOB)　was　more　vulnerable　to　BZC　than　ammonia　oxidizing　bacteria　(AOB).　When　activated　sludge　was　treated　only　once　with　0.023　g　BZC　center　dot(g　MLSS)(-1)　for　18　h,　partial　nitrification　was　attained　at　the　29th　cycle　with　NAR　of　97.46%　and　sustained　91　cycles　in　stability　tests.　Complimentary　DNA　sequencing　analysis　revealed　the　suppression　of　Nitrospira　was　the　reason　for　partial　nitrification.　Oligotyping　analysis　indicated　AOB　could　likely　resist　to　BZC　by　both　the　species　shifts　and　development　of　tolerance,　while　most　NOB　species　could　not　adapt　to　BZC.　This　study　revealed　the　feasibility　of　BZC　as　a　novel　NOB　inhibitor.